Folding machines for pre-punched cardboard pieces



Aug. 3, 1965 A. FREl 3,198,512

FOLDING MACHINES FOR PRE-PUNCHED CARDBOARD PIECES Filed 001;. 4, 1965Fig.3. f

United States Patent poration of Switzeriand Filed Oct. 4, 1963, Ser.No. 313,873 Claims priority, application Switzerland, Oct. 16, 1962,

12,236 8 Claims. (0. 27061) This invention relates to machines forfolding preformed cardboard blanks into boxes.

In the cardboard shaping industry and in particular, in themanufacturing of cardboard boxes, folding machines and combinationfolding-glueing machines are utilized to carry out more or lessautomatically the folding or preformed pieces into boxes.

The folding concerns more particularly the folding down of so-calledassembling flaps or glueing flaps.

Inrelation to the conveying direction of the cardboard pieces in suchmachines, such flaps are generally located in the front or at the sidesand their folding down is effected by suitable guides, stops orcompressed air jets in the course of transport of the pieces byconveying bands or belts. It also becomes necessary to fold or fold downnot only front flap elements preceding the piece to which they areattached, but rear flap elements as well. This is the case for piecesdestined for being formed as boxes with so-called automatic bottoms ordouble automatic bottoms.

The machine according to the present invention aims at allowing thefolding of the rear or posterior flap elements, following the piece towhich they are attached and onto one face of which they are to be foldeddown.

This result is obtained by providing for at least one endless band withan outside irregular surface which is placed normally near the conveyingplane of the pieces and practically in parallel with the latter, theband being driven in the same direction as that of the pieces, but at ahigher speed and arranged so as it can move away from this plane by aswinging around the shaft of its driving pulley the endless band in itsinitial position adapted to come into contact with the conveyed pieces.

The attached drawing shows an embodiment of a machine according to theinvention, given by way of example, and in a simplified form, whereinFIG. 1 is an elevational view diagrammatically illustrating the beginingof the folding process of a posterior flap of a cardboard piece.

FIG. 2 is a similar view schematically showing the main elements in thecourse of folding the said flap.

FIG. 3 is a view similar to that of FIG. 2, but at the completion of thefolding.

The piece 1 to be folded advances through the machine in the directionof the arrow 2 along the plane of the conveying device 3, constitutedfor instance by conveying belts running on guiding pulleys such as 4.

The machine frame which extends in the direction of the conveying device3 has not been represented for purposes of clarity. Moreover, neitherthe feeding devices nor the known folding and glueing contrivances whichare respectively located on the left and on the right of the drawing,have been shown. On the other hand two crossbars 5 and 6 appear insection joined to the said frame and support the main elements and to bedescribed hereafter.

The device is concerned with the folding down on the piece 1 of its rearor posterior flap 7 during the proper conveyance of the piece 1.

Between cross-bars such as 8, supported by the bars 5 and 6 is arrangeda driving assembly in which a pulley 10 is supported by a shaft 9 fordriving an endless belt 11 running over a second pulley 12. The belt 11has a lower 3,198,512 Patented Aug. 3, 1965 ice reach located adjacentthe plane 3 and is driven in the direction of the advancing piece 1; Abar 13 is interposed between the pulleys and keeps them at a suitabledistance,

so as to have the belt 11 stretched. A rod 14 projects from the bar 13beyond the pulley 10 in the general direction of advancement of thepieces.

Finally, the pulley 10 is rotatively integral with a pulley 15 driven bya power pulley 16 through the transmission belt 17.

The outside face of the endless conveying belt 11 is provided withsurface irregularities 18, in the form of teeth.

The pulleys 10 and 16 are rotated in the direction indicated by thearrows and, the strand of the belt 11 near the conveying device 3 at themoment of coming into contact with the conveyed pieces is practicallyparallel to the plane of the conveying device 3. The linear speed oftravel of the belt 11 is greater than that of the conveying device suchthat the following operation takes place.

The piece 1 arriving'under the belt 11 which is advancing at a greaterlinear speed, is engaged at the upper surface of the flap 7 by the teethof the belt which tend to raise the flap.

As the flap 7 is raised, it will as a result of the stiffness thereof,support and pivot the driving assembly via the belt 11 around shaft 9and the position of FIG. 2 will be assumed.

Therein, the flap 7 is raised to 7', its free edge having been drivenmore rapidly than the piece 1. Swinging around 9, the belt 11 and thepulley 12 will have on their turn passed to positions 11 and 12'.

A moment later, the folding down of the flap is completed as shown inFIG. 3. The flap is at 7", the piece at 1", whilethe belt 11 and thepulley 12 will have been lowered to the original position of FIG. 1.

The motions of the driving assembly already described are performedunder their own weight, since they can oscillate freely around the shaft9.

The pressure thus exerted by the unbalanced weight of the drivingassembly should be limited, preferably regulable, so as to insurecorrect operation without risking bending or crushing of the flap 7.

In this respect there is provided on the rod 14 an adjustablecounterweight 19, which is secured by the screw 20. The rod alsosupports an adjustable stop-screw 21, which contacts the bar 6 and thusmakes it possible to fix with great accuracy the lower resting positionof the assembly formed by the belt 11 and the pulley 12.

By this simple mechanism, of which it will be possible to arrange sideby side on the shaft 9 as many patterns as there will be flaps to befolded down in the conveying direction, it is possible to carry outwithout difiiculty and simply the desired folding operations.

It is noteworthy that the driving direction of the pulley It helps toincrease the propensity of the belt 11 to be applied against the pieceto be processed.

An inverted arrangement of that described is possible, that is thearrangement of the endless band under the conveying device and appliedagainst the piece due to the effect of counter-weights or springs.

In some cases, it will be advantageous to start the raising of the flap7 by means of a member located beneath the piece 1 and governed, inknown manner, by the pas sage of the piece 1.

What I claim is:

1. Apparatus for folding into the plane of an advancing blank, arearwardly extending flap which is foldably connected to the blank andinitially extends slightly upwardly with respect thereto, said apparatuscomprising means for supporting and advancing a blank thereon with theflap extending rearwardly and upwardly, means including a conveyedelement advancing in the same direction as the blank at a faster speedthereof and having an elongated surface spaced from the blank less thanthe upward extension of the flap for engaging the flap to pivotally foldthe same. and means pivotally supporting the aforementioned means in aninitial unbalanced position in which the conveyed element is tiltedrearwardly down by a magnitude of unbalanced weight to contact the flapand pivot the same, said flap having suflicient stiffness related to theunbalanced weight of the conveyed element to cause the conveyed elementitself to be pivotally moved upwardly by the flap itself as the latteris pivotally moved by the engagement of the flap with the conveyedelement, whereafter as the fiap is lowered into the plane of the blank,the conveyed element returns under its unbalanced weight towards itsinitial position to engage the opposite surface of the flap and completethe folding thereof into the plane of the blank.

2. Apparatus for folding into the plane of an advancing blank, arearwardly extending flap which is foldably connected to the blank andinitially extends slightly upwardly with respect thereto, said apparatuscomprising a conveyor device for supporting and advancing a blankthereon with the flap extending rearwardly and upwardly, a drivingassembly located adjacent the conveyor device and including a drivenbelt having a component of speed in the direction of advancement of theblank which is greater than the speed of advancement of th eblank, andmeans pivotably supporting the driving assembly in an initial positionin which said driven belt is spaced from the conveyor device less thanthe amount of upward extension of the flap such that the belt engagesthe flap and exerts a force thereon to pivotally raise the flap, saiddriving assembly having a magnitude of unbalanced weight which urges thedriving assembly to its initial position, the fiap having suificientstiffness to overcome the unbalanced Weight of the driving assembly andcause the driving assembly itself to be pivotally moved by the flap asthe flap is raised, said driving assembly returning to the initialposition thereof under its own weight as the flap passes the position inwhich it is raised perpendicular to the blank and is folded downwardlyonto the blank.

3. Apparatus as claimed in claim 2, wherein said driven belt issubstantially parallel to the blank when the driving assembly is in theinitial position.

4. Apparatus as claimed in claim 2, wherein said driving belt hasirregularities along the surface which engages the blank.

5. Apparatus as claimed in claim 4, comprising teeth on said driven beltto provide said irregularities.

6. Apparatus as claimed in claim 2, wherein said driving assemblycomprises a connected pair of spaced pulleys, one of which is driven,the belt passing around said pulleys, said means which pivotablysupports the driving assembly including means which pivotably supportsthe driven pulley such that the driving assembly undergoes pivotalmovement about an axis passing through the driven pulley.

7. Apparatus as claimed in claim 6, wherein said driving assemblycomprises an adjustable counterweight supported on a side of the drivenpulley opposite the other of the pulleys to adjust the magnitude ofunbalanced weight of the driving assembly.

8. Apparatus as claimed in claim 7, wherein said driving assemblycomprises a stop element for limiting the degree of pivotaly movement ofthe driving assembly about said axis through the driven pulley toestablish said initial position.

References Cited by the Examiner UNITED STATES PATENTS 2,770,475 11/56Jesus 270-68 2,902,810 9/59 McGihon 53-374 2,971,443 2/61 Striplin 93-363,110,488 11/63 Whitecar 270-68 EUGENE R. CAPOZIO, Primary Examiner.

1. APPARATUS FOR FOLDING INTO THE PLANE OF AN ADAVANCING BLANK, AREARWARDLY EXTENDING FLAP WHICH IS FOLDABLY CONNECTED TO THE BLANK ANDINITIALLY EXTENDS SLIGHTLY UPWARDLY WITH RESPECT THERETO, SAID APPARATUSCOMPRISING MEANS FOR SUPPORTING AND ADVANCING A BLANK THEREON WITH THEFLAP EXTENDING REARWARDLY AND UPWARDLY, MEANS INCLUDING A CONVEYEDELEMENT ADVANCING IN THE SAME DIRECTION AS THE BLANK AT A FASTER SPEEDTHEREOF AND HAVING AN ENLONGATED SURFACED SPACED FROM THE BLANK LESSTHAN THE UPWARD EXTENSION OF THE FLAP FOR ENGAGING THE FLAP TO PIVOTALLYFOLD THE SAME AND MEANS PIVOTALLY SUPPORTING THE AFOREMENTIONED MEANS INAN INITIAL UNBALANCED POSITION IN WHICH THE CONVEYED ELEMENT IS TILTEDREARWARDLY DOWN BY A MAGNITUDE OF UNBALANCED WEIGHT TO CONTACT THE FLAPAND PIVOT THE SAME, SAID FLAP HAVING SUFFICIENT STIFFNESS RELATED TO THEUNBALANCED WEIGHT OF THE CONVEYED ELEMENT TO CAUSE THE CONVEYED ELEMENTITSELF TO BE PIVOTALLY MOVED UPWARDLY BY THE FLAP ITSELF AS THE LATTERIS PIVOTALLY MOVED BY THE ENGAGEMENT OF THE FLAP WITH THE CONVEYEDELEMENT, WHEREAFTER AS THE FLAP IS LOWERED INTO THE PLANE OF THE BLANK,THE CONVEYED ELEMENT RETURNS UNDER ITS BALANCED WEIGHT TOWARDS ITSINITIAL POSITION TO ENGAGE THE OPPOSITE SURFACE OF THE FLAP AND COMPLETETHE FOLDING THEREOF INTO THE PLANE OF THE BLANK.